1. Field of the Invention
The present invention generally relates to a sealing structure employed in a thermally insulated box and, more particularly, to a sealing structure to be disposed in a gap between an inner wall surface of the thermally insulated box and a partition wall mounted within the box for dividing the interior space thereof into a plurality of compartments or chambers of different temperature conditions.
2. Description of the Prior Art
FIG. 5 of the accompanying drawings shows in a vertical sectional view a structure of a box-like body of a freezer/refrigerator unit equipped with a conventional partition wall sealing structure. Referring to FIG. 5, the interior space of a thermally insulated box-like body 1 having enclosure walls filled with foamed polystyrene resin also referred to as foamed styrol is divided into a freezing chamber 3 and a refrigerating chamber 4 by means of a partition wall 2. Reference symbols 3a and 4a denote front openings of the freezer/refrigerator which can be closed by doors (not shown) mounted pivotally.
FIG. 6 is an enlarged sectional view showing a region indicated by symbol A in FIG. 5. The partition plate 2, the interior of which is filled with foamed polystyrol, is supported within the thermally insulated box 1 by means of an angle member 5 fixedly secured to the thermally insulated box 1 by screws. A heat insulating packing 6 of a flexible or deformable material is interposed between the partition plate 2 and the thermally insulated box 1. Provided at a corner portion located between a rear wall surface 1a of the thermally insulated box 1 and the partition plate 2 is a caulking material 7 for filling any gaps possibly present between the thermally insulated box 1 and the partition plate 2 while preventing the heat insulating packing 6 from being exposed to the freezing compartment 3.
With the structure for sealing the partition wall described above, the caulking material 7 must be applied along the width of the partition wall 2 (i.e. in a direction perpendicular to the plane of FIG. 6). Consequently, when the region that the caulking material 7 is to be applied is very long as in the case of a large size freezer/refrigerator unit, troublesome and time consuming procedures are involved for the caulking, while skill is required to apply the caulking material.
Further, since the amount of moisture absorbed by the heat insulating packing 6 tends to increase during use of the freezer/refrigerator unit over an extended period of time, the heat insulation effect between the freezing compartment 3 and the refrigerating compartment 4 becomes degraded. As a result, water is likely to be frozen at a region near the angle member 5 due to heat transfer with the freezing compartment 3, and the ice thus formed grows progressively as time elapses, which is of course undesirable.